Important Tips for Using Petri Dishes
News 17 7 月, 2024
A Petri dish is a laboratory vessel used for culturing microorganisms or cells, consisting of a flat, circular bottom and a lid. Petri dishes are primarily made from two materials: plastic and glass. Glass dishes are commonly used for culturing plant materials, microorganisms, and animal cells, while plastic dishes, typically made from polyethylene, are suitable for laboratory tasks such as inoculation, streaking, and bacterial isolation, as well as for culturing plant materials.
The Petri dish was designed by Julius Richard Petri (1852-1921), a bacteriologist working under the German biologist Robert Koch, in 1887, and is therefore also known as the “Petri dish.” Due to their fragile nature, Petri dishes should be handled carefully during cleaning and use. After use, it’s best to clean the dishes promptly and store them in a safe, fixed location to prevent damage.
Types and Sizes of Petri Dishes
Petri dishes come in various sizes, including 60mm, 90mm, 55mm, 100mm, and 150mm in diameter.
Cleaning Petri Dishes
1.Soaking: Soak new or used glassware in clean water to soften and dissolve any residues. New glassware should be rinsed with tap water and soaked in 5% hydrochloric acid overnight. Used glassware often has protein and grease residues that are difficult to clean once dried, so they should be immersed in water immediately after use.
2.Brushing: After soaking, place the glassware in detergent water and scrub thoroughly with a soft brush, ensuring no dead angles and preventing surface damage. Rinse and dry the cleaned glassware, preparing it for acid soaking.
3.Acid Soaking: Acid soaking involves immersing the glassware in a cleaning solution (acid) to remove any remaining residues through strong oxidation. Soaking should last at least six hours, preferably overnight or longer. Handle the glassware with care.
4.Rinsing: Thoroughly rinse the glassware with water after brushing and acid soaking. The cleanliness of the glassware after acid soaking directly affects the success of cell culture. For manual cleaning, each item should be rinsed at least 15 times, followed by 2-3 rinses with distilled water, then dried or baked for future use.
5.Sterilization: Disposable plastic Petri dishes are typically sterilized by radiation or chemicals before being shipped.
Types of Petri Dishes
– Based on Use: Petri dishes can be classified as cell culture dishes and bacterial culture dishes.
– Based on Material: Petri dishes are made from plastic or glass. Imported and disposable dishes are usually made of plastic.
– Based on Size: Common sizes include 35mm, 60mm, 90mm, and 150mm in diameter.
– Based on Compartments: Some Petri dishes have 2 or 3 compartments for different uses.
– Material Categories: Glass dishes are used for plant materials, microorganism culture, and adherent animal cell culture. Plastic dishes, either disposable or reusable, are suitable for bacterial inoculation, streaking, and separation, and can also be used for plant materials.
Usage Precautions
– Cleaning and Sterilization: Ensure Petri dishes are clean and sterilized before use. Cleanliness impacts the pH of the culture medium, and residual chemicals can inhibit bacterial growth.
– New Dishes: Rinse new dishes with hot water and soak them in 1-2% hydrochloric acid for a few hours to remove free alkaline substances, then rinse twice with distilled water.
– Sterilization for Bacterial Culture: For bacterial culture, sterilize dishes using high-pressure steam (typically 6.8×10^5 Pa) at 120°C for 30 minutes, then dry at room temperature. Alternatively, dry heat sterilization can be used by placing dishes in an oven at around 120°C for 2 hours.
– Post-Sterilization: Only use sterilized Petri dishes for inoculation and culture.
By following these guidelines, you can ensure the successful and safe use of Petri dishes in your laboratory experiments.